Apparatus for heat-treating materials



Nov. 28, 1933.

H. ROTH 1,937,413

APPARATUS FOR HEAT TREATING MATERIALS Filed Feb. 25, 1932 2 Sheets-Sheet 1 b H 1 b d Nov. 28, 1933. H. ROTH 1,937,413

APPARATUS FOR HEAT TREATING rmaanns Filed Feb. 25, 1932 2 Sheets-Sheet 2 Patented Nov. 28, 1933 UNITED STATES PATENT OFFICE APPARATUS FOR HEAT-TREATING MATERIALS Application and in 6 Claims.

My invention relates to improvements in the method of and apparatus for drying, calcining, burning and/ or sintering argillaceous earth, gypsum, ore, and the like, and'the object of the improvements is to provide a method and an apparatus in which conglomeration of the said material being treated is prevented, and inwhich the heating gas has access to all the particles of the material, so that the heat required in the operation is small and a product of uniform and high quality is obtained.

It is known that raw cement material or the like may be heated by exposing the material together with hollow fire-proof heat interchanging bodies to a heating treatment in a furnace whereupon these heat interchanging bodies are separated from the material and afterwards fed in again mixed with fresh material;

In contrast to the above this invention comprises a rotating permeable foraminous drum in which solid filling bodies form a permeable layer which permits the material under treatment to pass from top to bottom and lets the heat gases pass through.

Compared with the devices known up to the present the invention offers the considerable advantages that the filling bodies layer is always maintained as a thing complete in itself, but that the filling bodies are continuously jumbled up by the rotation of the drum whereby the filling bodies always form new interstices and channels so that they continuously create new ramified ways on the one hand to let the material pass and on the other hand to conduct the heating gases; these ways are extraordinarily long and ramified. In consequence of this the raw material is exposed as much as possible to the heating gases in its travel so that the raw materials divided into smallest parts come into direct touch with the heating gases, thus realizing an extensive utilization of the heating gases. The procedure in the rotating permeable drum so far as it concerns the travel of the material shows a similarity to the working of a ball mill containing a layer of steel balls. These balls form between each other interstices which change continuously during rotation and permit the crushed material to pass through and the latter finally leaves the drum through the sieve casing. 1

For example raw materials in dry, wet or slurry condition are fed into the rotating drum partly filled with filling-bodies and equipped with a mantle which permits the gases to pass through and this drum is placed in a casing or the like through which the heating gases pass. 011. aq-

February 25, 1932, Serial No. 595,202,

Germany September 22, 1931 count of the continuous motion of the drum the material under treatment is very uniformly distributed by the filling bodies which are continuously disarranged and rolled round whereby all possible conglomerations are immediately destroyed. At the same time the heating gases passing through the drum act energetically by favourable utilization of the heat on all finely divided parts of the material which is in slow continuous motion.

The finished material may be finally taken out of the drum in one way or another, in order to be collected and carried off, etc. The heating gases for the drum may be taken from a special furnace or any other kiln e. g. rotary-kiln, shaft or grate-furnace.

The heating gas may be produced in a furnace of any known or preferred construction, for example in a revolving furnace, in a shaft furnace, in a tunnel furnace, or in a furnace having a grate.

For the purpose of explaining the invention several apparatuses suitable for carrying out the method have been illustrated in the accompanying drawings, in which the same letters of reference have been used in all the views to indicate corresponding parts. In said drawings,

Fig. 1 is a sectional elevation showing the apparatus and the furnace associated therewith,

Fig. 2 is a sectional elevation taken on the line 2-2 of Fig. 1, and

Fig. 3 is a sectional elevation showing a modification.

As per Figs. 1 and 2 a cylindrical drum 1) in a housing a rotates on a horizontal axis. The material to be treated is fed by means of a hollow shaft 0 and a tube 01 into the interior of the drum. The interior of the drum is partly filled with filling bodies b of metal, porcelain or the like.

In the casing there are baiiles e forcing the rising heating gases to pass through the openings of the drum b and the layer of filling bodies in the drum.

After having exerted their influence upon the mo material to be treated, in the interior of the drum, the heating gases leave the drum and enter the. chimney or a blower.

vThe heating gases are produced by a gratefurnace f and enter the lower end of the casing a by a side-opening g.

After having been treated suiliciently by the influence of the filling bodies b and of the heating gases the material leaves the drum, falls QQWILWaIds in the casing a and may be taken no out at the lower end and transported in some way or other.

Instead of a grate-furnace it is possible to use any other kind of furnaces as, for example; a

coal dust furnace, a gas furnace, or an oil fired furnace.

The casing as per Fig. 3 showing the application of the new device has at the lower end an inclined bottom it on which the material treated in the drum b slides to an attached rotary-kiln i where the material is further exposed to the infiuence of a burner is.

On leaving the rotary kiln i the heating gases rise and cause the heating of the material fed into the drum b.

If with this device cement clinkers are to be burnt the material is not only well dried in the drum b but also practically ready calcined, so that it needs only to be sintered in the rotary kiln.

Instead of a rotary kiln one may also use the already well known channel furnace or a shaft kiln whereby the waste gases of these appliances are also suitably led into the casing a.

With the new device a considerable saving in fuel consumption is obtained because the heating gases are extraordinarily utilized, and furthermore an absolutely uniform quality of the material to be burned is realized.

I claim:

1. Apparatus for calcining material comprising a foraminous drum rotatable on a horizontal axis, a layer of disintegrating bodies in said drum, said bodies consisting of heat-resistant material, a conduit entering axially of the drum arranged to feed material onto said layer of bodies, means for supplying a current of heated gas to the under side of the drum, bafiles extending lengthwise alongside the drum for directing'such gas against the under side of the drum, and means below the drum for carrying off the treated material.

2. Apparatus for treating material comprising a foraminous drum mounted for rotation about a substantially horizontal axis, a mass of durable disintegrating bodies in said drum, means for feeding material to said drum, means for supplying heated gas to the foraminous wall of the drum, and means for directing the gas substantially only to that part of the said wall which is covered by the mass of disintegrating bodies.

eemra of heated gas to pass through the .wall of the drum, and means for limiting the current of gas substantially to that part of the drum which is covered by the mass of disintegrating bodies.

4. Apparatus for heat-treatment of material comprising a foraminous drum mounted for rotation on a substantially horizontal axis, a mass of durable heat-resistant disintegrating bodies in said drum, means for supplying material to said drum, means for supplying hot gas to the ioraminous wall of said drum, and means for directing the gas substantially only to that part of the wall which is covered by themass o1 disintegrating bodies.

5. Apparatus for heat-treating material comprising a ball-mill having a foramlnous wall, a mass of durable disintegrating bodies confined in said mill and covering a substantial part of said wall, means for supplying material to said mill, means for directing a current of gas against said wall, and means for limiting access of said.

current substantially to an outer peripheral area corresponding to the inner peripheral area covered by said mass of disintegrating bodies to enhance the heat exchange between the gas and the material under treatment.

6. Apparatus for treating material comprising a foraminous drum rotatable on a substantially horizontal axis, a layer of disintegrating bodies in said drum, means for supplying material to said drum through an opening in one end of the drum said drum being otherwise closed, a chamber of substantial depth below the drum through which chamber the treated material falls after passing through the openings in the drum wall, an outlet at the bottom of the chamber, and means for supplying gas to said chamber, the chamber wall adjacent to the drum having means to limit access of the gas substantially to that portion of the drum wall which is covered by the mass of disintegrating bodies and the material intermingled therewith to enhance the heat exchange between said gas and the material under treatment.

HUGO ROTH.

Mil 

